1. Field of the Invention
The present invention relates to communications, and particularly, to a system and method for messaging and signaling a switched network environment.
2. Background of the Related Art
Generally, Common Channel Signaling (CCS) is a method separating traffic or bearer lines on which data is transferred from signaling lines on which messages and signals are sent. A network adopting CCS includes signaling points connected through signaling links, and bearer lines which may include multiple trunk circuits (channels). A signaling link refers to a physical connection between two signaling points. A route is a series of communication network links connected from an origination point to a destination point, and refers to a logical connection. A communication network adopting Signaling System No. 7 as the CCS method is considered in the present invention.
FIG. 1 is a block diagram showing a structure of a Signaling System No. 7 network formed between two switching systems. As shown therein, if a data transfer process is initiated from a certain self station 100 to a certain counterpart station 200, self station 100 may first determine a route A on which the signal is transmitted, then may select a circuit from a circuit group in a trunk which is included in the self station for transmission of the data. FIG. 1 also illustrates another system 300 logically connected to self station 100 and counter part station 200 by routes B and C, respectively.
FIG. 2 is a block diagram showing inner structures of self station 100 and of counter part station 200 and showing a physical connection structure from self station 100 to counter part station 200. As shown therein, the inner structure of self station 100 and of counter part station 200 which are similar to each other. Self station 100 includes a plurality of Access Switching Subsystems (ASS), 110 to (110+n), having trunk circuits for communicating with counter part station 200; a Man Machine Processor (MMP) 120 connected to the plurality of ASS 110 to (110+n) for maintaining and repairing the network; an operator terminal 130 for interfacing the MMP 120 and the operator; and a database 140 connected to the MIP 120 for storing information necessary for operation, maintenance, and repair.
The respective ASS 110 to (110+n) includes an Access Switching Processor (ASP), (110−1) to (110+n−1), controlling the state of the trunk circuit and the signal transmission process. For example, in case of route A from the self station 100 to counter part station 200 as shown in FIG. 1, self station 100 bundles trunk circuits which are allocated to the route A as link units and arranges the link units on a plurality of corresponding ASS 100 to (110+n). Therefore, when an unexpected error is generated on the ASP in the ASS, another ASS can be substituted. Thus, the signal transmission between self station 100 and the counter part station 200 through the route A can be performed stably.
As shown in FIG. 3A, the respective ASS 110 to (110+n) in the self station 100 may include 4096 trunk circuits, and the trunk circuits may be bound as link units. The trunk circuits of each link unit are allocated to a route.
Self station 100 stores the states of the trunk circuits in the database 140 and manages them, and counter part station 200 stores the states of the trunk circuits in a database 240 and manages them. The states of the circuits read and stored by self station 100 and by counter part station 200 are synchronized with each other, and therefore the signal transmission between self station 100 and counter part station 200 can be made normally. Therefore, self station 100 and counter part station 200 should continually check whether the states of the circuits read and stored by the two stations are synchronized or not.
In the background art, the states of circuits are inquired as a link unit. Therefore, in order to inquire as to the state of a circuit group allocated to a certain route, the operator must begin by identifying a specific ASS among the plurality of ASS which contain circuit(s) allocated to the route in question. When the operator enters the specific ASS, an identification code and a range of circuits into operator terminal 130 of self station 100, the specific ASS generates a Circuit group Query Message (CQM) according to the above command and transmits the message to counter part station 200.
When a Circuit group Query Response message (CQR) is returned from the counter part station 200, the specific ASS in self station 100 analyzes the CQR. In addition, the specific ASS determines whether or not the state of circuit group managed by self station 100 and the state of circuit group managed by counter part station 200 are synchronized with each other. If the states of the circuit groups managed by self station 100 and by counter part station 200 are not synchronized with each other, the specific ASS in self station 100 performs a recovery process for synchronizing the state information.
The range of circuit groups which will be inquired is set to be less than 32 in accordance with recommendations Q761 through Q763 of ITU-T (International Telecommunication Union-Telecommunication Sector) for signaling system No. 7. Therefore, if the operator does not recognize a link on which the state of a circuit has an error, or if there are many circuits which are not synchronized with those of counter part station 200 among the circuits allocated to a certain route and the circuits are dispersed in various links, the operator may be forced to query the state of all circuits within counter part station 200.
For example, if the operator inputs a command for querying the state of a circuit group such as “ASS=0, identification code of the circuit which will be inquired =0, and the range of the circuit group which will be inquired=32” into operator terminal 130 of self station 100, a CQM is generated and circuit state query is performed for the link corresponded to the identification code 0˜31 of the circuits which will be inquired among the circuits which are disposed on a first ASS (ASS0) 110. When the query is completed, the operator inputs a command for querying the state of a circuit group such as “ASS=0, identification code of circuit which will be inquired=32, and the range of circuit group=32” again into operator terminal 130. As in the method described above, the operator may then input a command for querying the states of circuit group such as “ASS=n, identification code of circuits which will be inquired=N, and range of circuit group which will be inquired=R (1˜32)” into the operator terminal 130, and thereby query circuit state of all links inside self station 100.
Several disadvantages exist with current systems and methods. For example, according to the background method of querying the state of a circuit group in the switching system, the circuit group state query is made by link unit. Where the state query must be performed for all circuit groups, the operator must perform repeated operations. Therefore the method is inconvenient and a long time is needed to inquire the state of all circuit groups.
In addition, in order to inquire the state of a certain circuit group allocated to a certain route in the self station, an operator must know which circuits are disposed on each subsystem of self station 100, and which routes each circuit is allocated to. This is an inconvenient requirement. Further, the background method for querying circuit group state in the switching system requires too much operating time; thus operating efficiency is greatly lowered. Moreover, a recovery process must be performed when the states of the circuit managed by self station 100 and of the circuit managed by the counter part station 200 are not synchronized with each other. However, the recovery process is not described clearly in the recommendation. Other problems also exist with background systems and methods for monitoring circuit group state in switched networks.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.